Neuromuscular stimulation (the electrical excitation of nerves and/or muscle to directly elicit the contraction of muscles) and neuromodulation stimulation (the electrical excitation of nerves, often afferent nerves, to indirectly affect the stability or performance of a physiological system) and brain stimulation (the stimulation of cerebral or other central nervous system tissue) can provide functional and/or therapeutic outcomes. While existing systems and methods can provide remarkable benefits to individuals requiring neuromuscular or neuromodulation stimulation, many limitations and issues still remain. For example, existing systems often can perform only a single, dedicated stimulation function.
A variety of products and treatment methods are available for neuromuscular stimulation and neuromodulation stimulation. As an example, neuromodulation stimulation has been used for the treatment of erectile dysfunction. Erectile dysfunction (ED) is often referred to as “impotency.” When a man has impotency, he cannot get a firm erection or keep his penis erect during intercourse. There are some common diseases such as diabetes, Peyronie's disease, heart disease, and prostate cancer that are associated with impotency or have treatments that may cause impotency. And in some cases the cause may be psychological.
A wide range of options exist for the treatment of erectile dysfunction. Treatments include everything from medications, simple mechanical devices, psychological counseling, and surgery for both external and implantable devices.
Both external and implantable devices are available for the purpose of neuromodulation stimulation for the treatment of erectile dysfunction. The operation of these devices typically includes the use of an electrode placed either on the external surface of the skin, an anal electrode, or a surgically implanted electrode. Although these modalities have shown the ability to provide a neuromodulation stimulation with positive effects, they have received limited acceptance by patients because of their limitations of portability, limitations of treatment regimes, and limitations of ease of use and user control.
Implantable devices have provided an improvement in the portability of neuromodulation stimulation devices, but there remains the need for continued improvement. Implantable stimulators described in the art have additional limitations in that they are challenging to surgically implant because they are relatively large; they require direct skin contact for programming and for turning on and off. In addition, current implantable stimulators are expensive; owing in part to their limited scope of usage.
These implantable devices are also limited in their ability to provide sufficient power which limits their use in a wide range of neuromuscular stimulation, and limits their acceptance by patients because of the need to surgically replace the device when batteries fail, or the need to frequently recharge a rechargeable power supply.
More recently, small, implantable microstimulators have been introduced that can be injected into soft tissues through a cannula or needle. Although these small implantable stimulation devices have a reduced physical size, their application to a wide range of neuromuscular stimulation application is limited. Their micro size extremely limits their ability to maintain adequate stimulation strength for an extended period without the need for frequent replacement, or for recharging of an internal rechargeable power supply (battery). Additionally, their very small size limits the tissue volumes through which stimulus currents can flow at a charge density adequate to elicit neural excitation. This, in turn, limits or excludes many applications.
It is time that systems and methods for providing neuromuscular stimulation address not only specific prosthetic or therapeutic objections, but also address the quality of life of the individual requiring neuromuscular and neuromodulation stimulation.